The invention discloses a method for extracting cell wall combined biological demulsifiers, which belongs to the technical field of industrial microorganisms. The method comprises the following steps of: pretreating dry demulsification thalli powder of cell wall combined biological demulsifiers, mixing and stirring the dry power with alkali liquor and obtaining the cell wall combined biological demulsifiers through centrifugation, neutralization, concentration and freeze drying. The method has the advantages that the extractive demulsification effect is good, the extraction efficiency is high, the demulsification active substance extraction is complete, the biological demulsifier purification verification and the biodemusifier demulsification mechanism are favorably and further disclosed, and theoretical foundation can be provided for biodemusifier culture and large-scale industrial application.